Steam trap



May 10, 1938.

- F. R. DUNN STEAM TRAP Original Filed Feb. 15, 1935 2 Sheets-Sheet l lllll May 10, 1938. R N 2,117,056

. STEAM TRAP Original Filed Feb. 15, 1935 I 2 Sheets-Sheet 2 Patented May 10, 1938 UNITED STATES PATENT OFFICE American District Steam Company,

North Tonawanda, N; Y., a corporation of New Y ork Original application February 15, 1935, Serial Divided and this application June 24, 1936, Serial No. 87,061

11 Claims.

This invention relates to steam traps such as are variously used to remove condensation from steam distribution systems; to prevent entrance of steam to condensation meters; and on the out- 5 let of heaters or other heat transmission equipment. In pressure systems the trap may be of the gravity or drip type, while in vacuum heating systems a thermostatically controlled trap should be used.

One object of the invention is to provide a steam trap of extremely compact form but having a considerable capacity in relation to its overall dimensions so that it will require only a small space yet serve a system requiring an ordinary trap of much larger size.

A. further object of the invention is to provide a steam trap of extremely rugged construction both in its main structure and operating parts which may be economically manufactured and sold at a low price for universal use.

Still another object of the invention is to provide a trap which may be opened for cleaning or repair without disconnecting the same from the heating line, and in which all operating parts are carried by a single section of the casing so cons ructed that when it is removed all the parts are exposed and rendered accessible.

Certain features of the proposed trap form the subject-matter of my application Serial No. 6,733. filed February 15. 1935. now Patent No. 2.097.401. granted October 26, 1937. and the present case is a divisional application based thereon.

The subject-matter of the present case as one of its main features involves a novel arrangement of the valve and valve seat whereby the operating life and efficiency of the trap are greatly prolonged. The proposed valve arrangement offers advantages both in wearing qualities and efficiency of operation over prior types. Among 40 other features of such construction are the reversibility of both the valve and seat, and while the idea of reversibility is known in the art the particular form and mounting of the proposed elements according to the present invention is considered generally superior to prior devices.

One practical embodiment of the invention is illustrated in the accompanying drawings, wherein:

Fig. l is a view in central vertical elevation of the new trap and showing all operating parts;

Fig. 2 is an elevation from the inside of the removable side portion of the trap of Fig. l which carries all operating parts, but from which certain parts have been removed for clarity;

Fig. 3 is a detailed view of the valve and valve seat;

Fig. 4 is an end view of the valve mounting shown in Fig. 3;

Fig. 5 is a perspective of the detachable mounting for the valve seat which also supports the valve and its operating mechanism.

The trap comprises a main body portion l and a removable end cover unit II. The body portion houses a trap chamber E2 of generally rounded contour but having no accurately definable shape. As conventionally the chamber houses a valve l3 and its spherical float control l4, hereafter to be described, and by reference to Fig. 1 it will be observed that the shape is such as to provide adequate space for the operation of the float and the mounting of the valve. maximum available space in relation to the size of the trap, and the greatest possible capacity for the minimum overall trap dimensions.

The inlet port IE to the chamber I2 is located in the central top area of the main trap body H). To enable simple connection of the trap in a heating line the discharge outlet [6 is located at the bottom of the trap in vertical alignment with the inlet I but the same is separated from the trap chamber l2 by the chamber bottom wall ll. As will be seen in Fig. l the outlet l6 communicates with a horizontal passage underlying the trap chamber and this in turn connects with a vertical continuation located in the removable cover unit II and having a horizontal opening in its wall controlled by valve I3 through which liquid is discharged from the chamber l2 for conduction to the outlet It, all as further to be explained.

The chamber bottom wall I! has a downward slope leading to a depending well l8 which increases the capacity of the trap and which must be filled during operation of the trap before the level of condensate rises sufiiciently to lift the float and open the valve I3. A blowout port I9 is provided in the end wall 20 of the well. The end wall 2| of the chamber l2 curves upwardly from the Well and at its upper area is rounded to merge with the top 22 and opposite curved side walls of the chamber.

Projecting laterally beyond the central vertical portion of the opposite concave end wall 23 of the chamber I2 is an extension structure having inner and outer spaced walls 24 and 25 which define a vertical discharge throat or passage 26. The chamber end wall 23 and the extension structure are constructed to constitute the cover unit H, which as best seen in Fig. 2 is removably mounted by bolt connections on the main trap body l0 through abutting flanges 21 and 28. The walls of the vertical throat 26 of the cover unit turn inwardly beneath the chamber I2 at their lower end to provide a horizontal throat extension 29 terminating in a port 39 in the plane of the cover flange. The upper wall 3| of the horizontal throat portion 29 terminates in a flange 32 which abuts flange 33 formed on the end of the chamber bottom wall H. An outlet chamber or passage 34 is formed in the main trap body beneath wall ll. Such space communicates at its lower end with the main outlet port l6 and through port 341 communicates with the discharge passage 26 in the removable cover unit.

Located centrally of the side wall 24 between the discharge throat 26 and the main chamber I2 is an opening 35 surrounded on the chamber side by a boss 36 serving as the liquid discharge port for the chamber. Detachably secured to the boss by screws 31, 38 is a mounting and member 39, best shown in Figs. 2 and 5, having a central opening 40 aligned with and of the same diameter as the opening 35. Supported in the passage thus formed is a removable elongated valve seat 4| of suitable bore to properly pass the liquid to be discharged from the chamber l2 into passage 26 from whence it passes underneath the chamber l2 and out through outlet port l6. It will be appreciated that by locating the valve passage horizontally and above the bottom of the chamber, and further through the provision of the depending well l8 below the level of the sloping chamber bottom wall ll, there is no opportunity for the valve opening to become clogged.

The valve seat 4| is of a reversible type and formed for this purpose with similar ends equally suited as seats for the valve body I3. Centrally of the valve seat is a peripheral rib 42, best shown in Figs. 1 and 3, receivable in an annular recess 43 surrounding the opening 40 at the inner face of the detachable mounting 39 and held against a sealing gasket 44 at the face of boss 36. The valve seat is thus supported in'the aligned openings in the boss and mounting against both rotation'and longitudinal movement. By loosening screws 31 and 38 and removing member 39 the valve seat may be reversed and the parts reassembled to bring the opposite end of the seat into exactly the same position occupied by the end previously used in coaction with valve l3.

Projecting inwardly from the face of mounting member 39 over the valve seat are a pair of ears 45, 46, pivotally supporting a'stub crank arm 41 to the short upper end of which is threaded the metallic spherical float !4. The shorter lower end 48 of the arm 41 is bifurcated to provide a recess 49, shown in Figure 3, in alignment with on'the shank is slightly greater than the thick-' ness of the crank arm and the inner faces of the spaced valve portions are beveled or rounded 01f,-

all to permit the valve to have a limited movement in the crank arm and insure that the active valve end automatically locates itself for positive engagement with the valve seal when moved to closed position. The valve shank is supported on a fulcrum in recess 49 of the arm provided by a small pin 10 positioned to allow a slight clearance between the shank and inner end of the recess so as to facilitate wabbling movement of the valve in finding its seat.

The. utility of the loose fulcrum mounting of the valve IS in the crank arm and positive seating action of the valve are in part attributable to the fact that the two ends of the valve are identical, being of the same size and weight so as to balance or counterbalance each other.

The parabolic contour of the active valve end portions 50 and 5| has two distinct advantages. Thus the seat engaging surface area of the valve has a gradual slope relative to the axis of the valve and the bore of the valve seat so that as the valve moves inwardly the curved and gradually inclined valve surface will make initial engagement with the end of the valve seat and result in any necessary shift of the valve in its mounting to insure absolute alignment with the seat as the valve moves to completely closed position. The construction is particularly advantageous where as here the valve operates in a horizontal position.- It will be further appreciated that the'contour of the valve is such that the same will be equally effective with valve seats of different bores. 'Ihisis important in that different size valve openings are required depending on the flow in the system in which the trap is to be installed. 7

Another advantage of the parabolic valve shape over more conventional constructions arises fromthe fact that the increase or decrease in the restriction of the passage through the seat is gradualand at the same time very substantial with but a slight inward or outward movement of the valve body; and, further, the valve requires but a relatively small movement of the crank arm 41 to move the same between fully open and fully closed positions. The valve is quick acting and very sensitive to changesin level of the liquid collecting in the trap. In the illustrative trap shown in Fig. 1, the valve is mounted roughly one inch from the pivot of the crank arm. The floatend of the crank arm is also veryshort to minimize the necessary sizeof the trap as previously explained. Movement of the float under changes in liquid level through an arc of 35 degrees will move the valve between its full open and closed positions and any lesser movement will-result in substantial change in the degree of restriction of the passage by the va1ve.-

To insure sealing engagementwith the parabolic valve body,-the-bored ends of the valve seat may be beveled although sharp. edges have been.

Both the valve and valveindicated in Fig. 3. seat are preferably made of chrome nickel. noncorrodiblesteel to promote long life and minimize corrosion. To limit the movement ofthe float and valvea stop lever 53 is formed on the crank arm 49 adapted to engage the top wall of the valve seat mounting 39 when the float is raised to its maximum position, thereby preventing undue strain and sticking of the operating parts, and, particularly, eliminating the possibility of the float hitting or rubbing against the upper wall of the chamber which conditions might cause denting and/or leakage of the float.

Referring again to the discharge passage 26 formed in the detachable side unit, it will be observed that the same extends well towards the upper end of the trap substantially above the float-controlled valve discharge from the main trap chamber and terminates in an enlarged portion 55 adjacent wall 54 formed by a depression 56 in the central portion of the wall of the inner passage 24 which projects into the main chamber 26 at a point above the level to which liquid rises in the chamber. The wall 54 is provided with a bore 51 through which air accumulating in the trap chamber may be vented.

The air vent as just described may be thermostatically controlled. In the embodiment of the drawings I have illustrated a removable thermostatic valve arrangement forming the subjectmatter of my application Serial No. 6,733, the same being readily removable and replaceable so that the trap may be employed both in pressure and vacuum heating systems.

As more fully brought out in said other application the bore 5! in wall 54 is provided with a valve seat 58 communicating with an antichamher or alcove 59 in open communication with the upper part of the end 23 of the main trap chamber I2. A thermostatic valve 60 of the bellows type is therein housed, the same having at its underside a tapered valve 6| coactive with the seat 58. As the temperature rises in the trap the thermostat expands to close the valve. In the main chamber a bafile 66 is disposed across the inlet I5 to prevent the inflow of fluid from impinging directly on the thermostat and also to guard against the escape of steam before it has condensed in the trap chamber. The upper end of the antichamber 59 is provided with a port 62 formed in the detachable side section of the trap which permits the thermostatic valve to be inserted or removed depending on the use to which it is to be put. Port 62 is closed by a screw cap 63, such cap at its inner end opposing a flange 64. The thermostatic unit 60 is provided at its upper end with a plate 65 which is engageable between the screw and flange and is thus secured in operative position.

From the detailed description here given it will be understood that the trap providestwo separate outlets from the main chamber both communicating with a common discharge passage which extends along one end of the chamber and leads to the outlet port beneath the chamber. The lowermost main outlet port of the chamber is controlled by the float actuated valve and serves to discharge the condensate. The upper auxiliary outlet from the upper end of the chamber serves to vent accumulated air and as indicated may be controlled by a removable thermostatic valve which operates entirely independently of the float controlled liquid discharge valve.

When the trap here described is to be employed in a pressure heating system the thermostatic valve will preferably be removed and the trap will then function as a simple drip or gravity trap. As liquid and steam enter the trap chamber I2 through the inlet I5 the level of the condensate will rise to a. point where the float will open the valve I3 allowing the liquid to pass out through port into the discharge passage 26, thence into discharge chamber 34 and finally escape through outlet port I6. The valve opening provided between the antichamber 59 by the bore in seat 58 may be left open so as to function as a vent to bypass air accumulating in the chamber to the trap outlet. If it is iound that part of the steam instead of condensing in the trap chamber escapes through the vent, the valve seat 58 can be replaced by one of smaller bore or a plug can be inserted to close the vent completely and a manually controlled valve of conventional form inserted at a suitable point in the wall of the main chamber to provide for the escape of air and prevent the building up of undesired pressure.

For use in vacuum heating systems the thermostatic valve unit will be inserted in place in the antichamber 59 and will thus function to automatically control the escape of air from the trap when placed in operation. As the heat of the trap chamber increases with the entrance of uncondensed steam, the thermostatic valve will close to prevent the escape of the steam through the air bypass vent. It will be noted that while the thermostat is built into the trap and in communication with the main chamber it is protected in the antichamber by baffie 56 against exposure and undesired response to the steam as it first enters the trap. In the present device the operation of the float controlled liquid discharge valve is the same in both vacuum and pressure systems and it will be evident that the general operation of the trap is entirely independent of the presence or absence of the thermostatic valve.

In case the trap requires cleaning or repair the detachable side unit I I may be removed without disturbing the pipe connections to the main trap body I 0. The detachable unit carries all the operating parts of the trap including the main discharge valve and seat, the bellcrank valve mounting and float, and the thermostatic air venting valve, and when removed exposes all such parts for inspection, reversal of the reversible discharge valve and seat, or adjustment, cleaning and inspection.

I claim:

1. In a steam trap, a discharge opening in the Wall of the trap chamber, a member in the trap chamber detachably secured to said chamber wall opposite said wall opening and having an opening of similar bore aligned with and forming an extension of the wall opening, an elongated valve seat element detachably supported in and fitting the bores of both the aligned openings and secured in position by the detachable member, and a valve located in the chamber beyond the bore in the detachable member controlling the discharge from the trap chamber, said valve being coactive with the valve seat and supported by the detachable member.

2. In a steam trap, a discharge opening in the wall of the trap chamber, a member detachably secured to said chamber wall opposite the discharge opening having an opening therein, the openings in the wall and the detachable member being of uniform bore and being aligned with each other, a reversible valve seat comprising a tubular element snugly fitting in both the aligned openings and extending through the detachable member to the inner face thereof, said tubular element having a peripheral rib located midway between its ends adapted tobe clamped between the wall and detachable member, thereby to secure the tubular element against longitudinal movement in the aligned openings, a valve controlling discharge from the valve chamber coactive with the inner end of the tubular element, the tubular element having similarly formed ends each providing a valve seat, and being reversibly securable in the aligned openings with either end seat positioned to engage the control valve.

3- In a steam trap, a discharge opening in the side wall of the trap chamber, a member in the chamber detachably secured to said chamber side wall, a tubular valve seat adapted to be removably secured in said discharge opening in the side Wall by said detachable member and with its inner end facing the trap chamber, float actuating means pivotally mounted on and supported by said detachable member, and a valve mounted on said actuating means at a point in the chamber beyond the inner end of the detachable member for swinging movement into and out of engagement with the inner end of the valve seat.

4. In a steam trap, a trap chamber having a removable side wall, a discharge opening for the chamber in said removable side wall, a valve seat in the discharge opening projecting inwardly beyond the wall into the trap chamber, a valve coactive with the valve seat and float actuating means therefor, and a mounting in the chamber supporting said valve, valve seat and valve actuating means assembly, said mounting being detachably secured to the inner side of the removable Wall of the chamber opposite the discharge opening.

5. In a steam trap, a discharge port in the side wall of the trap chamber, a pivoted mounted bellcrank comprising angularly related upper and lower arms, a float in the chamber fixed to the end of the upper arm, the lower arm of the bellcrank projecting downwardly o-pposite said chamber side wall and being provided with a recess, said recess opposing and extending in the direction of the discharge port, and a reversible counterbalanced control valve for the discharge port loosely seating in said recess.

6. In a steam trap, a discharge port in the wall of the trap chamber, a stub bellcrank pivotally mounted in the chamber adjacent the discharge port, a float in the chamber secured to one arm of the stub bellcrank, and a valve having two opposing parabolic surfaces, one of said surfaces acting as a counterbalance for the other, said valve being loosely mounted on the opposite arm of the stub bellcrank in position for operative engagement with the discharge port.

'7. In a steam trap, a horizontally extending discharge port in the side wall of the trap chamber having an end providing a valve seat, a pivoted valve supporting arm, means responsive to changes in level of liquid in the trap chamber for actuating said arm, and a Valve body having an active end of parabolic contour and a weight on the other end counterbalancing said active end, said active end coactive with the valve seat of the horizontally extending discharge port and loosely mounted in the supporting arm.

8. In a steam trap a horizontally extending discharge port in the side wall of the trap chamber, a pivotally mounted stub arm supported ad jacent the discharge port, actuating means responsive to changes in liquid level in the trap chamber secured to one end of the stub arm, and a reversible valve body having head of tapering curved contour coactive with the end of the horizontal discharge port and a weight on the valve body'counterbalancing the head, said reversible valve body being loosely mounted in the second end of the stub actuating arm.

9. In a steam trap, a horizontally extending discharge port in the side wall of the trap chamber, a pivotally mounted valve supporting arm, means responsive to changes in liquid level in the chamber actuating said arm and a valve body having a shank portion loosely supported by the valve arm, an enlarged valve head at one end of the shank engageable with the discharge port under actuation of the valve arm, and a weight formed at the other end of the shank counterbalancing the valve head.

10. In a steam trap, a horizontally extending discharge port in the side wall of the trap chamber, a pivotally mounted valve supporting arm, means responsive to changes in liquid level in the chamber actuating said arm and a valve body of dumb-bell shape comprising similarly shaped valveheads at opposite ends of the body and a reduced shank spacing and connecting the opposing valve heads, one valve head counterbalancing the other, a slot in the valve supporting arm adapted to receive the valve shank, and means for reversibly supporting the valve loosely in said slot with either valve head in operative position for engagement with the discharge port.

11. In a steam trap, a one piece casing housing a trap chamber, a cover detachably secured to the casing and forming a removable wall for one side of the trap chamber, an inlet and an outlet in the casing, a port in said removable wall communicating with the outlet, a removable valve seat for said port carried by and removable with said wall, a supporting plate carrying a removable fioat controlled valve mechanism for said port detachably secured on the chamber side of the removable wall and holding the valve seat in position for engagement by the float valve.

FREDERICK R. DUNN 

